Ferromagnetic relaxation in NiFe/Si(001) alloy thin films

Author(s): Jose.R.Fermin

In this paper, we present a study on the ferromagnetic relaxation in thin films. For this, a series of NiFe alloyed thin films were sputtered onto Si (001) wafers by dc magnetron sputtering, and then characterized by inplane ferromagnetic resonance (FMR). The FMR linewidth (ïÂÂH) is studied as a function of the in-plane angle, ïÂªH, film thickness, t, and temperature, T. We show that the mechanisms responsible for the magnetization relaxation in NiFe thin films, involve angular dispersions of the uniaxial anisotropy,ïÂÂ ïÂª u, and Gilbert damping,G.Both,ïÂÂ ïÂª u andG, followthe 1/t law expected for interface phenomena. As function of temperature, the ferromagnetic linewidth decreases as T increases, in accordance with the theory of thermal activated electron-lattice scattering processes.